Display screen or portion thereof with a graphical user interface



FIG. 1 is a front view of a first embodiment of a display screen or portion therefore with a graphical user interface according to the claimed design; and,

FIG. 2 is a front view of a second embodiment of a display screen or portion therefore with a graphical user interface according to the claimed design.

The shading in the figures indicate a contrast in appearance.

The broken line showing of the display screen or portion thereof forms no part of the claimed design. The remaining broken line showing of graphic elements and text forms no part of the claimed design. 

CLAIM The ornamental design for a display screen or portion therefore with a graphical user interface, as shown and described. 